Ft ir 8400 instrument

Chemicals were purchased from Merck chemical company (Darmstadt, Germany). TLC was applied to detect end of the reactions of the synthesized compounds. Melting points were determined in open capillary tubes and presented uncorrected. Structures of the target compounds (4a–4i) were confirmed by FT-IR, ¹H-NMR, ¹³C-NMR and Mass spectra. FT-IR spectra were recorded on Shimadzu FT-IR-8400 instrument in KBr disk. ¹H-NMR spectra were recorded on Bruker AC-500 MHz FT-NMR using DMSO-d6. Mass spectra were recorded on Jeol-D300 spectrometer. Elemental analyses were carried out with a Perkin-Elmer Model 240-c apparatus (Perkin Elmer, Norwalk, CT, USA), and the results of the elemental analyses (C, H, N) were obtained within ± 0.4% of the calculated amounts.

NMR spectra were recorded on a Bruker Avance DPX 500 MHz instrument in DMSO-d₆ (Bruker, Rheinhausen, Germany). Chemical shifts were provided relative to TMS. Elemental analysis was measured using a Heraeus CHN-O-Rapid analyzer (Heraeus, Hanau, Germany). Fourier-transformed IR (FT-IR) was carried out on a KBr pellet using a Shimadzu FT-IR-8400 instrument (Shimadzu, Duisburg, Germany). TGA-DTA was measured using a PL Thermal Science STA-1500 Polymer Thermal Analyser (PL Thermal Science, Boxhill, UK). Field emission scanning electron microscopy (FE-SEM) was carried out on FEI NOVA NANOSEM 450 (Thermo Fisher Scientific, Waltham, MA, USA).